I got a Verizon GS5 at the end of September. I started with Message+, and I loved the ability to text from other devices like my laptop, Nexus 7, and now-wi-fi-only iPhone, and how it keeps things synced. The messages are stored and synced via Verizon servers for something like 30 days or maybe some number of messages (some thousands?).
But I've since switched to more stock Android (or is it Samsung?) Messages, because of some customization available there that was not available in Message+. Verizon servers and the Message+ clients on my other devices still sync and receive my incoming text messages, and I can still text from them. But my outgoing messages from those other clients do not show up in my Messages app, where they would in my Message+ app.
It's not perfect, but it's a compromise that I'm okay with for now. I don't even quite remember what customization I could do in Messages that swayed me to it, so I'll likely revisit that decision at some point and look at the Message+ app again. (OH! One contributing factor to my switch was that Message+ kept crashing, especially after one of the updates...maybe both 4.4.3 and 4.4.4.)